The present invention relates to doors with synthetic resin skins and synthetic resin cores, and to methods for making such doors.
For many years, exterior doors were fabricated from solid wood slabs in order to provide strength and good weathering characteristics as well as an attractive appearance. Many of these doors were sculpted to provide panels, and other doors interfitted panels into apertures formed within the basic door structure. Because of the cost of such solid slab doors, and the need to find wood slabs which were relatively free from imperfections to provide a good surface for such doors, many companies made doors which employed veneers adhered to a core of less expensive wood. Unfortunately, such veneers have had a tendency to delaminate and/or to split over years of exposure in an exterior environment, particularly one which provides substantial thermal cycling and direct exposure to rain and sun.
In addition to the economic pressures, a number of communities have adopted building codes requiring that doors utilized in certain locations have fire resistant, or at least fire retardant properties. This led to the development of doors with metal skins secured to a wooden or metal skeleton to provide the desired strength for the structure. Various materials including foamed synthetic resin have been used as the core material in these doors to provide insulation between the metallic faces to reduce heat and sound transfer therebetween. Unfortunately, such metal skin doors cannot be stained to simulate wood, and they are generally readily identifiable as metal skins rather than wood which is in aesthetic disadvantage. Moreover, the metal skins are readily dented.
Two decades ago Owens-Corning Fiberglass introduced into the marketplace doors which employed compression molded skins formed from fiberglass reinforced polyester. These skins were molded with panels to simulate conventional wooden doors and also employed an expanded synthetic resin between the skins to fill the space therebetween. The fiberglass skins could be stained to appear wood-like and they could also be molded with embossed patterns. Since that time, a number of companies have manufactured doors employing such molded fiberglass skins. Many of these doors have utilized a rectangular wooden frame of stiles and rails to provide the structural strength for the assembly.
It is an object of the present invention to provide a novel method for making a door employing molded synthetic resin skins which may be practiced easily and economically.
It is also an object to provide such a method for making a door which substantially resists warping and which also will successfully resist the bending forces when the door is closed with substantial force.
Another object is to provide such a method for making a door which is attractive and exhibits long life, and which may be easily assembled in a door frame.